(286e) Sequential Flow Membraneless Microfluidic Fuel Cells with Porous Electrodes

A novel convective flow membraneless microfluidic fuel cell with porous electrodes is described. In this fuel cell design, the fuel flows through the anode and across a gap to the cathode. An oxidant is introduced into the gap between anode and cathode and advects downstream of the cathode. This fuel cell differs from previous membraneless designs in that the fuel and the oxidant flow in series, rather than in parallel, enabling independent control over the fuel and oxidant flow rate and the electrode areas. The cell uses formic acid as a fuel and potassium permanganate as the oxidant, both contained in a sulfuric acid electrolyte. The results show that increasing the electrolyte concentration reduces the cell Ohmic resistance, resulting in larger maximum currents and peak power densities. Increasing the flow rate delays the onset of mass transport and reduces Ohmic losses resulting in larger maximum currents and peak power densities. A comparison between the sequential flow and other flow patterns is discussed.